Pancreatic juice contains digestive enzymes secreted by the pancreas that aid in the breakdown of macronutrients. Amylase digests carbohydrates by breaking down starch into maltose, while lipase breaks down triglycerides into free fatty acids and glycerol. These enzymes are essential for proper digestion and absorption in the small intestine. Pepsin is a gastric enzyme, and lactase, maltase, sucrase, and isomaltase are brush border enzymes, not pancreatic enzymes. Understanding the enzyme composition of pancreatic juice is crucial in diagnosing and managing pancreatic exocrine insufficiency and guiding surgical interventions involving the pancreas and duodenum.

Reference: Gray's Anatomy, Richard Drake et al., 42nd Edition.